I am trying to hook into the compilation process of my code to generate some additional files, in a way similar to ppx_deriving. Now it looks like ppx_type_conv is the easiest way to do so, but I can’t get my deriver to be picked by ppx_driver, when compiling ppx_type_conv complains: rror: ppx_type_conv: 'foo' is not a supported type type-conv generator.